matrix_multiplication.java

import java.io.*;
import java.util.*;

public class matrix_multiplication{

public static void main(String[] args) throws Exception {
Scanner scn = new Scanner(System.in);

		int r1 = scn.nextInt();
		int c1 = scn.nextInt();

		int[][] arr = new int[r1][c1];

		for(int i = 0; i < arr.length; i++){
			for(int j = 0; j < arr[0].length;j++){
				arr[i][j] = scn.nextInt();
			}
		}

		int r2 = scn.nextInt();
		int c2 = scn.nextInt();

		int[][] arr2 = new int[r2][c2];

		for(int i = 0; i < arr2.length; i++){
			for(int j = 0; j < arr2[0].length;j++){
				arr2[i][j] = scn.nextInt();
			}
		}


		if(c1 != r2){
			System.out.print("Invalid input");
			return;
		}

		int[][] prd = new int[r1][c2];

		for(int i =0; i < prd.length;i++){
			for(int j =0; j<prd[0].length;j++){
				for(int k = 0; k<c1;k++){
					prd[i][j] += arr[i][k] * arr2[k][j]; 
				}
			}
		}

		
		for(int i = 0; i < prd.length; i++){
			for(int j = 0; j < prd[0].length;j++){
				System.out.print(prd[i][j] + " ");
			}
			System.out.println();
		}	
 }

}